1. Field of the Invention
The present invention relates to a switch including a breaker such that a switch for turning an electric circuit on/off includes a breaker for interrupting the electric circuit.
2. Description of the Prior Art
An apparatus including an electric circuit, which is operated by a power source, and a load, the operation of which is controlled by the electric circuit, has a structure of a type employed widely and provided with, in addition to a switch for turning the electric circuit on/off, a breaker for preventing generation of an excess current due to a malfunction or a failure of the electric circuit and heat caused from the excess current.
In an electric car having a conventional control circuit, a mechanical switch 4 for turning an operating circuit 3 on/off is, an example of which is arranged as illustrated in a block diagram shown in FIG. 9, connected to a DC power source 1 through a breaker 2. A load 5 is connected to the operating circuit 3 through the foregoing mechanical switch 4. As a result, if the load 5 is, for example, short-circuited, the breaker 2 is instantaneously operated to interrupt the electric current from the DC power source 1 so that generation of heat due to flow of an electric current exceeding a rated value from the power source is prevented to improve the reliability.
However, the foregoing conventional structure arranged such that the breaker 2 and the switch 4 for the operating circuit 3 are disposed individually inevitably encounters undesirable enlargement of the overall size. Moreover, since the contact for the breaker 2 and that for the switch 4 are provided independently, the cost cannot be reduced.